Disclaimer:

The Nonindigenous Occurrences section of the NAS species profiles has a new structure. The section is now dynamically updated from the NAS database to ensure that it contains the most current and accurate information. Occurrences are summarized in Table 1, alphabetically by state, with years of earliest and most recent observations, and the tally and names of drainages where the species was observed. The table contains hyperlinks to collections tables of specimens based on the states, years, and drainages selected. References to specimens that were not obtained through sighting reports and personal communications are found through the hyperlink in the Table 1 caption or through the individual specimens linked in the collections tables.

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Common name: cutbow trout

Identification: Rourke and Wallace (1978); Behnke (1992).

Size: 2.46 kg.

Native Range: Not applicable; artificial hybrid. Can occur "naturally" where both species come in contact through stocking.

Alaska	Hawaii	Puerto Rico & Virgin Islands	Guam Saipan

Hydrologic Unit Codes (HUCs) Explained
Interactive maps: Point Distribution Maps

Means of Introduction: Intentionally stocked as sport fish.

Status: Maintained by stocking either the hybrid or a parent species where the other parent species naturally occurs (usually stocking the rainbow in cutthroat native range).

Impact of Introduction: Native cutthroat are being replaced by introduced rainbow trout through hybridization and competition. Where the two species naturally co-occur, they rarely hybridize (Sigler and Miller 1963; Behnke, personal communication). Seiler and Keeley (2009) showed that cutthroat trout had reduced growth rates in the presence of cutthroat-rainbow hybrids in laboratory experiments.

Remarks: Recorded from the Southwest as early as 1918 (Sigler and Miller 1963). Private hatcheries sell hybrids between rainbows and Snake River cutthroats (Behnke, personal communication). These two species do not hybridize in areas where both are native (Sigler and Miller 1963). Hybrid trout have not been stocked in Oklahoma (Pigg, personal communication).

References: (click for full references)

Insider Viewpoint. 2001. Fishing Records – Nevada. Insider Viewpoint Magazine. 3 pp.

Rasmussen, J.L. 1998. Aquatic nuisance species of the Mississippi River basin. 60th Midwest Fish and Wildlife Conference, Aquatic Nuisance Species Symposium, Dec. 7, 1998, Cincinnati, OH.

Seiler, S.M., and E.R. Keeley. 2009. Competition between native and introduced salmonid fishes: cutthroat trout have lower growth rate in the presence of cutthroat-rainbow trout hybrids. Canadian Journal of Fisheries and Aquatic Sciences 66:133-141.

Sigler, W.F., and R.R. Miller. 1963. Fishes of Utah. Utah Department of Fish and Game, Salt Lake City, UT.

Other Resources:
Fact Sheet for Oncorhynchus clarkii - USGS Nonindigenous Aquatic Species Database

Fact Sheet for Oncorhynchus mykiss - USGS Nonindigenous Aquatic Species Database

Author: Fuller, P.

Peer Review Date: 5/20/2013

This information is preliminary or provisional and is subject to revision. It is being provided to meet the need for timely best science. The information has not received final approval by the U.S. Geological Survey (USGS) and is provided on the condition that neither the USGS nor the U.S. Government shall be held liable for any damages resulting from the authorized or unauthorized use of the information.